The present invention relates to a new and improved clamping or chucking apparatus for clamping cutter blades or cutters of a gear cutting machine, during the grinding of such cutter blades, at a grinding machine, wherein the cutter blades are mounted in a cutter head and the cutter head is rotatable about a cutter head axis, and further, is pivotably mounted for pivotable movement about a pivot axis.
Clamping equipment of the heretofore described type serves for use at grinding machines for attachment of cutter heads of gear cutting machines during the grinding of the cutter blades or cutters which have been mounted at the cutter heads.
In German Pat. No. 902,351 there is disclosed a clamping apparatus of the type generally described above, wherein the cutter head is rotatable about a cutter head axis and is pivotable about a horizontal pivot axis which is arranged at right angles to the cutter head axis. In this equipment the cutter head is further rotatable about an additional, vertically arranged rotational axis. Such clamping apparatus is likewise displaceable at all sides in a horizontal plane and is elevationally adjustably arranged.
For setting the inclination of the cutters, prior to grinding thereof, with this state-of-the-art clamping apparatus it is necessary to initially rotate the cutter head about its own axis, then to pivot it about the pivot axis and the vertical axis of rotation. Thereafter, through displacement in the aforementioned plane, and equally, by carrying out an elevational adjustment, there must be then compensated the prior formed spacing between the grinding wheel and the surface of the cutter blade which is to be ground. Hence, in the grinding machine there must be provided long paths for the displacement of the clamping apparatus in the mentioned plane and also in elevation. This is associated with the drawback that there is required a correspondingly large amount of space.
With this prior art clamping apparatus there are provided scales and associated markers which are arranged concentrically with respect to the different axes. Since the radius, at which the scales and markers are arranged and read or adjusted, is smaller than the radius at which moves the surface of the cutter blade to be ground, any possible reading or adjustment inaccuracies are carried over.
Also carried over and transmitted to the bearings are the forces exerted by the grinding wheel or disk upon the cutter head. Although these forces, which arise at the grinding machine, for which there is provided the prior art clamping apparatus, are relatively small, nonetheless there must be feared deformations of the individual parts of the clamping apparatus. It is for this reason that the heretofore known clamping apparatus possesses an exceptionally heavy construction.
There is also known to the art from U.S. Pat. No. 2,135,894 a further construction of clamping apparatus of the general type heretofore described, wherein the cutter head is rotatable about a cutter head axis and can be pivoted about a horizontal pivot axis arranged perpendicular to the cutter head axis. In this case, once again the cutter head is further rotatable about an additional vertically arranged axis of rotation.
With this prior art construction of clamping apparatus there is required a great deal of free space, in order to be able to bring the elements, supporting the cutter head, into positions enabling grinding of the cutter blades with the standard inclination angle of the relevant flanks of the cutter blades. The effective line of the forces, transmitted during grinding at the cutter head, extend far outside of the support surfaces of the bearing arrangement of the different pivotable and adjustable elements. This in turn requires an extremely rigid and robust construction of the bearing arrangement and also the individual elements.
In order to be able to displace the part of the clamping apparatus which is pivotable about a horizontal axis, for instance from a lower position into an upper position, the entire weight of this part must be overcome, which in conjunction with the bearing friction which is to be overcome and which is to be expected from the nature of the support or bearing arrangement for such part, corresponds to an appreciable expenditure in force. Therefore, there are required specially constructed devices in order to move these parts, which, in turn, again increases the space requirements of such clamping apparatus. Owing to the play which is present within the individual devices, and which is needed for displacement of the individual elements relative to one another, with this prior art equipment design there is likewsie an impairment of the accuracy.